George e



(No Model.)

G. E. HART.

MANUFACTURE OF WATGH'BALANGES. No. 364,107. Patented May 31, 1887.

N. PETERs. PhomLilhngn hnr, washing-m. D. c.

. UNITED STATES PATENT OFFICE.

GEORGE E. HART, OF WATERBURY, CONNECTICUT, ASSIGNOR TO THE 4 \VATERBURYWATCH COMPANY, OF SAME PLACE.

MANUFACTURE OF WATCH-BALANCES.

' SPECIFICATION forming part of Letters Patent No. 364,107, dated May31, 1887.

Application filed July 22, 1586. Serial No. 108,159. (No model.)

To all whom, it may concern.-

Be it known that I, GEORGE E. HART, of Waterbury, in the county of NewHaven, and in the State of Connecticut,haveinvented certain new anduseful Improvements i nthe Manufacture of Watch-Balances; and I dohereby declare that the following is a full, clear, and exactdescription thereof, reference being had to the accompanying drawings,in which- Figure 1 is a perspective view of the blank from which-mybalance is made as cut from a sheet of metal. Fig. 2 is a like view ofthe same after having one ofits faces recessed. Fig. 3 is a perspectiveview of said blank after having passed through the forming-dies. Fig. 4is a like view of the same after the fin has been trimmed from aroundits periphery. Fig. 5 is a perspective view of said blank after thesurplus metal has been trimmed from its central portion. Fig. 6 is alike view of the same after having been repressed, and Fig. 7 is aperspective view of the completed blank.

Letters of like name and kind refer to like parts in each of thefigures.

The design of my invention is to enable watch-balances to be more easilyand quickly made than has heretofore been practicable; and to this endit consists, principally, in the method employed for blanking out awatchbalance, substantially as and for the purpose hereinafterspecified.

It consists, further, in the method employed for blanking out andcompleting a watch-balance, substantially as and for the purposehereinafter shown.

In the carrying of myinvention into practice, a disk, A, is out from asheet of metal, and a circular recess, a, is then out within one of itssides by any suitable tool. The blank A is next subjected to the actionof two dies, one of which dies has a plain face, while within the faceof the other die is formed a recess that corresponds in size and shapeto the like features of the proposed balance-wheel, the result being, asshown in Fig. 3, the production in relief upon the recessed side of saidblank of the rim a and peripheral projections a which resemble thescrews of an expansion balance-wheel. The blank A is next submitted tothe action of trin'lming dies, which remove the surplus metal or finfrom around its periphery and leave it in the shape seen in Fig. 4,alter which other trimming-dies cut from within its rim all of the metalexcept such as forms the central arm, a, as shown in Fig. 5. The nextoperation consists in sub jecting the blank A to the action of dieswhich correspond to those first used and operate to give a perfect formto each portion of said blank, and to compress and render dense themetal of the same, the result being shown in Fig. 6. The final operationconsists in rendering the inner and outer edges of the blank A perfectlysmooth by shaving from the same with suitable dies any surplus stock inthe shape of a fin, which leaves said blank in the form shown in Fig. 7,ready to be completed by the formation of a central opening for thereception of a staff. I

The balance-wheel thus produced has a per- .fect shape, and if properlyplaced upon a stafi will run perfectly true. Its density so much exceedsthat of ordinary metal that there ismuch less expansion and contractionunder variations of temperature than in balances of usual construction,and its cost is but a fraction of that heretofore required for theproduction of solid balances.

Having thus described my invention, what I claim is v l. The methodemployed for blanking out watch-balances, which consists in impressingthe general form of the rim and peripheral projections of a balance upona disk of metal by means of a forging'die, and then forming the centralarm and removing the surplus metal from the inner and outer peripheriesof said rim by means of a cutting-die, substantially as and for thepurpose specified.

2. The method employed for forming watchbalances, which consists inimpressing the general form of the rim and peripheral projections of abalance upon a disk of metal by means of a forging-die, then forming thecentral arm and removing the surplus metal from the outer andinnerperipheries of said rim by In testimony that I claim the foregoing Imeans of a. cutting-die, .and, lastly, subjecting have hereunto set myhand this 18th day of the wheel thus formed to the action of a forg-May, A. D. 1886. ing-die that is provided with a recess which 5corresponds to the size and shape of the fin- GEORGE E. H ART.

, \Vitnesses: ished balance, substantiallyas and for the pur- GEO. S.PRINDLE, pose shown. HENRY G. HAZARD.

